Improper Integrals with the HP-15C LE & CE

[Namir]

In a thread-based conversaion with Valentin Albillo, Valentin mentioned some improper intgerals to test with the 16-point Gaussian Quadrature (the subject of that thread in the HP-41C software) that I had posted. I decided to test some of these integrals with the fast HP-15 LE and CE. Here are the reslts!

intgeral of 1/sqrt(x) for x = 0 to 1 (accurate solution is 2)
HP-15 LE gave 1.9998705
HP-15C CE gave no solution

intgeral of cos(x)*log(x) for x = 0 to 1 (correct is -0.9460830703670)
HP-15C CE gave -0.946082894
HP-15C LE gave -0.946083028 (slighly more accurate)

intgeral of 1/√(-Ln(x)) (correct is 1.77245385091)
HP-15C CE gave no solution
HP-15C LE gave no solution

In the case where I noted that a calculator "gave no solution" the machine kept running for several minutes flashing "running". Given that the LE and CE are fast calculators, one would expect a relatively quick answer (even if it is a rough approximation).

Namir